The Passover night's own destroyer (hamashchit), sharing the identical root - reversed here to strike Jerusalem rather than spare it.
Then he cried in my ears with a loud voice, saying, “Cause those who are in charge of the city to draw near, each man with his destroying weapon in his hand.”
For Yahweh will pass through to strike the Egyptians; and when he sees the blood on the lintel, and on the two door posts, Yahweh will pass over the door, and will not allow the destroyer to come in to your houses to strike you.
This continues the ch.8-11 temple vision, moving from witnessed idolatry directly into enacted judgment - what Ezekiel saw in ch.8 is now punished within the same vision.